Email this article 
Post a Comment 
A dosimetric analysis of the aeroformTM tissue expander in radiation therapy
Abstract
Purpose: The aim of this study is to evaluate the effects of the metallic reservoir and the use of gas within the Aeroform™ tissue expander with respect to the radiation dose distribution.
Methods: Dosimetric effects of using a metallic reservoir within a breast tissue expander during external beam radiotherapy were investigated. To view the internal components of the reservoir, it was removed from the tissue expander and imaged on a Varian AS500 electronic portal imager. To calculate the relative density of each component within the reservoir, an ionization chamber within solid water was used to measure the dose and compared to a simulation within the Pinnacle treatment planning system (TPS). To examine the relative dose profile along the length of the reservoir, the reservoir was exposed on EBT3 film and analyzed using SNC Patient™. In-vivo Dosimetry was performed using a RANDO® Woman phantom. Thermo-luminescent dosimeters were placed within the wax bolus enveloping the tissue expander.
Results: Imaging the reservoir on the electronic portal imager revealed it consists of 3 distinct components. The densities assigned in the TPS, which resulted in calculated doses which matched the measured doses were; Section 1 = 0 g/cm3, Section 2 = 2.8 g/cm3 and Section 3 = 0.7 g/cm3. Relative dose reductions were observed due to the metallic case; Section 1 = 20%, Section 2 = 40% and Section 3 = 30%. Entrance doses ranged from 2.39 - 2.53 Gy for both the medial and lateral beams. Exit doses ranging from 1.10 - 1.71 Gy were observed in both beams. There was a significant difference in measured and calculated doses at exit locations in the beam.
Conclusion: Dosimetric effects due to the metallic reservoir within the Aeroform breast tissue expander have been demonstrated and have been observed to be significant. To increase the dosimetric accuracy when contouring, individual components of the reservoir should be distinguished. Our in-vivo experiment showed that dose homogeneity was difficult due to the metallic reservoir and we recommend stringent patient dose monitoring when using this expander during radiotherapy.
-----------------------------
Cite this article as: Tran T, Ding W, Subramanian B, Melven L, Chao M, Farrow H, Baker C. A dosimetric analysis of the aeroformTM tissue expander in radiation therapy. Int J Cancer Ther Oncol 2014; 2(3):020316. DOI: 10.14319/ijcto.0203.16
Keywords
References
Dean C, Chetty U, Forrest AP. Effects of immediate breast reconstruction on psychosocial morbidity after mastectomy. Lancet 1983; 1:459-62.
Wilkins EG, Cederna PS, Lowery JC, et al. Prospective analysis of psychosocial outcomes in breast reconstruction: one-year postoperative results from the Michigan Breast Reconstruction Outcome Study. Plast Reconstr Surg 2000; 106:1014-25.
Motwani SB, Strom EA, Schechter NR, et al. The impact of immediate breast reconstruction on the technical delivery of postmastectomy radiotherapy. Int J Radiat Oncol Biol Phys 2006; 66:76-82.
Ascherman JA, Hanasono MM, Newman MI, Hughes DB. Implant reconstruction in breast cancer patients treated with radiation therapy. Plast Reconstr Surg 2006; 117:359-65.
Krueger EA, Wilkins EG, Strawderman M, et al. Complications and patient satisfaction following expander/implant breast reconstruction with and without radiotherapy. Int J Radiat Oncol Biol Phys 2001; 49:713-21.
EBCTCG (Early Breast Cancer Trialists' Collaborative Group), McGale P, Taylor C, er al. Effect of radiotherapy after mastectomy and axillary surgery on 10-year recurrence and 20-year breast cancer mortality: meta-analysis of individual patient data for 8135 women in 22 randomised trials. Lancet 2014; 383:2127-35.
AirXpanders Inc. (Palo Alto C. Aeroform. 2013. Available from: http://www.airxpanders.com/
Ashland. Gafchromic Film. Available from: http://www.gafchromic.com/
PTW. RW3 Solid Water. Available from: http://www.ptw.de/acrylic_and_rw3_slab_phantoms0.html
IBA-Scanditronix. Ionization detectors. Available from: http://www.iba-dosimetry.com/complete-solutions/radiotherapy/relative-dosimetry/detectors
Labs P. RANDO. Available from: http://www.phantomlab.com/products/rando.php
Moni J, Saleeby J, Bannon E, et al. Dosimetric impact of the AeroForm tissue expander in postmastectomy radiation therapy: An ex vivo analysis. Pract Radiat Oncol 2014; (In Press).
Damast S, Beal K, Ballangrud A, et al. Do metallic ports in tissue expanders affect postmastectomy radiation delivery? Int J Radiat Oncol Biol Phys 2006; 66:305-10.
P. Naturelle 133 Breast Tissue Expander. 2013; Available from: http://www.allergan.com/products/medical_aesthetics/tissue_expanders.htm
Thompson RC, Morgan AM. Investigation into dosimetric effect of a MAGNA-SITE tissue expander on post-mastectomy radiotherapy. Med Phys 2005; 32:1640-6.
DOI: http://dx.doi.org/10.14319/ijcto.0203.16
This work is licensed under a Creative Commons Attribution 3.0 License.
International Journal of Cancer Therapy and Oncology (ISSN 2330-4049)
© International Journal of Cancer Therapy and Oncology (IJCTO)
To make sure that you can receive messages from us, please add the 'ijcto.org' domain to your e-mail 'safe list'. If you do not receive e-mail in your 'inbox', check your 'bulk mail' or 'junk mail' folders.
Number of visits since October, 2013